JP2006314120A - Radio communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance transmission efficiency of data and to enhance communication quality without complicating a decoding circuit of a receiver in a radio communication system. <P>SOLUTION: A payload is disassembled into a plurality of data units and a header of the payload is given to each data unit. A plurality of codewords are generated by giving error correction codes to each data unit to which the header is given, a packet for storing the plurality of codewords is generated and transmitted. The receiver reproduces the plurality of data units using each corresponding header, checks errors of the plurality of reproduced data units using each corresponding error correction code and performs retransmissions request to data units in which the errors are detected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio communication system, a radio communication method, and a radio communication apparatus for transmitting and receiving data in packet units.

  Conventionally, wireless communication systems that transmit and receive data in packet units have been put into practical use. Such wireless communication systems are applied to private networks such as wireless LAN systems, public network access lines, and the like.

  In a wireless communication system, data errors are generally likely to occur. For this reason, a wireless communication system often has a function for checking the normality of data and a function for correcting erroneous data. Here, the function for checking the normality of the data is realized by, for example, a cyclic code check (CRC) code. The function of correcting erroneous data is realized by, for example, an error correction code (ECC).

  By the way, the wireless communication system often employs a protocol for checking, for each packet, that a transmission packet has been received by a receiving device. For example, in FIG. 12, the station A decomposes user data into a plurality of data units to generate a plurality of packets, and sequentially transmits these packets to the station B. On the other hand, each time the B station receives a packet, it returns a corresponding ACK message to the A station. At this time, the station A transmits the next packet when it can receive the ACK message corresponding to the transmission packet. Therefore, when a large amount of data is transmitted, “data transmission” and “reception of an ACK message” are repeatedly transferred, resulting in a decrease in data transmission efficiency.

  In the above system, if the data length of each packet is increased, the data transmission efficiency is improved. However, if the data length of each packet is increased, the circuit scale of the error correction decoding circuit provided in the receiving device will increase. Further, if the data length of each packet is increased, the time required for the process of decoding the received signal and reproducing the data becomes longer, so that a problem of data delay occurs in communication that requires real-time performance. Therefore, considering the downsizing / cost reduction of the decoding circuit and communication quality such as delay characteristics, there is a limit to increasing the data length of each packet.

  As a method for solving this problem, for example, as shown in FIG. 13, a method of storing and transmitting a plurality of codewords in each packet has been proposed. Here, a code word is a unit of data that can be error-corrected by a block code independently of each other. Therefore, an error correction code (ECC) is assigned to each code word.

  If a packet having such a configuration is used, even if the length of each code word is short, the number of times the ACK message shown in FIG. 12 is returned decreases, and the data transmission efficiency increases. If the codeword length is short, the circuit scale of the error correction decoding circuit provided in the receiving apparatus can be reduced, and the data delay is reduced. A technique using a packet having such a configuration is suggested in, for example, Japanese Patent Laid-Open No. 4-144335. It is also proposed in IEEE 802.11 (particularly IEEE 802.11e).

  As described above, various proposals have been made for techniques for improving data transmission efficiency in a wireless communication system, but further improvements including improvement of communication quality are desired.

  An object of the present invention is to further improve data transmission efficiency in a wireless communication system. Another object of the present invention is to improve communication quality without complicating the decoding circuit of the receiving apparatus.

  In the wireless communication method of the present invention, data is divided into a plurality of data units, communication control information of the data is assigned to each of the plurality of data units, and a plurality of data units to which the communication control information is assigned A plurality of codewords are generated by giving an error correction code to each of the data, a packet storing the plurality of codewords is generated and transmitted, and a plurality of data is obtained using corresponding communication control information. The unit is reproduced, each of the reproduced data units is checked for errors using the corresponding error correction code, and a retransmission request is made for the data unit in which the error is detected.

  According to this method, even when an arbitrary codeword among a plurality of codewords cannot be reproduced, other codewords are reproduced using the communication control information set for each codeword. Can do. Therefore, even if an error occurs in an arbitrary code word (particularly, the first code word), it is not necessary to request retransmission for all the code words.

  According to the present invention, data transmission efficiency is improved in a wireless communication system. Further, communication quality can be improved without complicating the decoding circuit of the receiving apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a wireless communication system according to an embodiment of the present invention. Here, this system includes a master station (master) 1 and a plurality of slave stations (slaves) 2-1 to 2-N. The master station 1 has a function of transmitting and receiving radio signals to and from each of the slave stations 2-1 to 2-N. On the other hand, each of the slave stations 2-1 to 2-N has a function of transmitting / receiving a radio signal to / from the master station 1. Further, this system is not particularly limited, but is a wireless LAN system, for example.

  FIG. 2 is a configuration diagram of the wireless communication apparatus according to the embodiment of the present invention. Here, this wireless communication apparatus corresponds to the master station 1 or the slave stations 2-1 to 2-N shown in FIG. FIG. 2 shows only a function for transmitting generated user data and a function for reproducing user data from a received signal.

  The encoder 11 encodes user data. In addition, although an encoding system is not specifically limited, Here, a block code shall be employ | adopted. That is, when the encoder 11 receives user data, the encoder 11 divides the user data into data units (or data blocks) of a predetermined length, and gives an error correction code (ECC) to each data unit. Thereby, one or a plurality of codewords are generated. The spread modulation unit 12 spreads the code word data output from the encoder 11. Then, the RF front end unit 13 wirelessly transmits the signal output from the spread modulation unit 12.

  The RF front end unit 21 receives a radio signal. The spread demodulation unit 22 reproduces the code word by despreading the received signal. The decoder 23 extracts user data from the codeword reproduced by the spread demodulation unit 22 and outputs it. At this time, if there is an error in the user data, the error is corrected using an error correction code. In addition, the decoder 23 generates a determination signal indicating whether there is an error in the user data or whether the error in the user data can be corrected.

  FIG. 3 is a diagram illustrating a configuration of a wireless packet used in the wireless communication system of the embodiment. The transmission device stores user data in one or more wireless packets and transmits the user data. Further, the receiving device extracts user data from the received wireless packet.

  User data is divided every predetermined data length. Thereby, a plurality of data units are generated. If the data length of the user data is shorter than the predetermined data length, one data unit is generated.

  Each data unit is individually encoded. That is, an error correction code (ECC) as a check bit is assigned to each data unit. Here, the error correction code is a code for checking a bit error of the data unit, and is a code for correcting the error when there is an error, and is created by a known technique. Thus, one or a plurality of code words are generated. The code word is sometimes called an FEC (Forward Error Correction) block. Further, the error correction code of the block code is not particularly limited. For example, a Reed-Solomon code, a Hamming code, a BCH code, a Golay code, a Fire code, and the like can be used.

  One or more codewords are stored in the wireless packet. In the example shown in FIG. 3, K code words are stored. Here, the maximum value of “K” is not particularly limited, but is about 20, for example.

A packet header is added to the head of the wireless packet. In this packet header, at least one or both of the following information is set.
(1) Code word number information (2) Coding parameter information The “first data” described in the claims of the present invention is, for example, the code word number information or the coding parameter information. However, the “first data” is not limited to such information, and may correspond to the entire packet header. On the other hand, the “second data” is, for example, one or a plurality of code words shown in FIG.

  The code word number information is information indicating the number of code words stored in the wireless packet. In the example shown in FIG. 3, “number of codewords = K” is obtained. Here, if the length of each code word is predetermined, the data length of the wireless packet can be recognized based on this code word number information. For example, if the length of each codeword is 228 bytes and 20 codewords are stored in the wireless packet, “4560 (= 228 × 20) bytes” is obtained as the data length of the wireless packet. Will be.

  By the way, generally, in a wireless communication system, a receiving device needs information indicating the data length of a wireless packet when reproducing received data. For example, in the format defined in IEEE 802.11, the data length is displayed by the “frame length” provided in the PLCP header. However, in order to express the data length, many bits (that is, areas) are required. Specifically, for example, in a PLCP header defined in IEEE 802.11, a 2-byte area is used to display “frame length”.

  On the other hand, in the wireless communication system of the embodiment, the data length of a wireless packet is represented by codeword number information. Here, the number of codewords stored in each wireless packet is about 20, and can be represented by several bits of information. That is, in the system of the embodiment, it is sufficient if an area of 1 byte is secured in order to display the data length of the wireless packet.

  As described above, in the system according to the embodiment, the area necessary for representing the data length of the wireless packet is reduced, and therefore, the data transmission efficiency is higher than that of an existing wireless communication system (for example, IEEE 802.11). Become. Since the code word number information is set in the packet header, which is an area where no block code is applied, the code word number information can be extracted without performing the block code decoding process in the receiving apparatus. Therefore, there is no delay in calculating the data length of the wireless packet in the receiving device.

  The encoding parameter information is information that displays an encoding method used when generating a code word. Specifically, for example, when a Reed-Solomon code is used as the encoding parameter information, the encoding rate (for example, data: 208 bytes, error correction code: 20 bytes, etc.) is set. However, the information set as the encoding parameter information is not limited to this. For example, information indicating the type of block code to be used (Reed-Solomon code, Hamming code, BCH code, etc.), interleaving Information indicating presence / absence, information indicating switching of block code / convolutional code, and the like may be set.

  This encoding parameter information is used when a receiving device that has received a wireless packet decodes data stored in the packet, but is also used to determine whether or not to decode the packet. Can do. Hereinafter, a function for determining whether or not to execute the decoding process using the encoding parameter information will be described.

  FIG. 4A is a diagram illustrating the encoding parameters set for each communication path. Here, the data transmitted from each of the slave stations 2-1 to 2-3 to the master station 1 is encoded by the encoding method specified by the encoding parameter A, and the master station 1 transmits each of the slave stations 2-1. It is assumed that the data transmitted to ˜2-3 is encoded by the encoding method specified by the encoding parameter B. The master station 1 is assumed to include a decoder that decodes data encoded by the encoding method specified by the encoding parameter A. Each of the slave stations 2-1 to 2-3 includes a decoder that decodes data encoded by the encoding method specified by the encoding parameter B.

  In the wireless communication system, the slave station 2-1 transmits data to the master station 1. In this case, as shown in FIG. 4B, encoding parameter information for displaying the encoding parameter A is set in the radio packet transmitted from the slave station 2-1. When receiving the packet, the master station 1 refers to the encoding parameter information. At this time, the encoding parameter information is “A”. Therefore, the master station 1 determines that the codeword stored in the received packet can be decoded, and starts the decoding process. Thereby, the master station 1 acquires the data transmitted from the slave station 2-1.

  Note that the wireless packet transmitted from the slave station 2-1 is also received by the slave stations 2-2 and 2-3. However, the slave stations 2-2 and 2-3 do not include a decoder that decodes data encoded by the encoding method specified by the encoding parameter A. For this reason, the slave stations 2-2 and 2-3 determine that the codeword stored in the packet cannot be decoded when the encoding parameter information of the received wireless packet is “A”. That is, even if the slave stations 2-2 and 2-3 receive the packet transmitted from the slave station 2-1, they do not start the decoding process. Therefore, it is avoided to perform decoding processing on data that cannot be decoded as a result, which contributes to reduction of power consumption.

  On the other hand, when data is transmitted from the master station 1 to the slave station 2-1, encoding parameter information indicating the encoding parameter B is set in the wireless packet as shown in FIG. 4C. Yes. Here, the destination address of this data is “slave station 2-1”. However, this destination address is assumed to be written in the code word as part of the user data.

  In this case, the wireless packets transmitted from the master station 1 are received by the slave stations 2-1 to 2-3, respectively. At this time, the encoding parameter information set in this packet is “B”. Accordingly, each of the slave stations 2-1 to 2-3 determines that the codeword stored in the received packet can be decoded, and starts the decoding process. Only the slave station specified by the destination address obtained by decoding the codeword takes in the received data. As a result, only the slave station 2-1 can reproduce the data transmitted from the master station 1.

  FIG. 5 is a configuration diagram of a decoder having a function of determining whether or not to execute decoding processing based on encoding parameter information. This decoder is provided in the master station 1 or the slave stations 2-1 to 2-N.

  The header extraction unit 31 extracts a header from the received packet and sends it to the encoding parameter extraction unit 32. At this time, one or more codewords stored in the received packet are sent to the decoding unit 34. The encoding parameter extraction unit 32 extracts encoding parameter information from the header extracted by the header extraction unit 31.

  The comparison unit 33 has a function as a control means for controlling the decoding unit 34, compares the encoding parameter information extracted by the encoding parameter extraction unit 32 with the preset encoding parameter information, An instruction to be given to the decoding unit 34 is created based on the comparison result. Specifically, if the one set of encoding parameter information matches each other, the decoding unit 34 is instructed to execute the decoding process. If the one set of encoding parameter information is different from each other, The decoding unit 34 is instructed to stop the decoding process. Here, the “predetermined encoding parameter information” specifies, for example, an encoding method corresponding to a decoding process executed by the decoding unit 34 in the own apparatus. Therefore, when the comparison unit 33 receives a packet that stores data that can be decoded by the decoding unit 34, the comparison unit 33 instructs the decoding unit 34 to execute decoding processing, and the packet that stores data that cannot be decoded by the decoding unit 34. Is received, the decoding unit 34 is instructed to stop the decoding process.

  The decoding unit 34 determines whether or not to execute the decoding process according to the instruction given from the comparison unit 33. Specifically, the decoding unit 34 is activated only when the set of encoding parameter information matches each other, that is, only when a decodable codeword is stored in the received packet. .

  As described above, in the system of the embodiment, since the encoding parameter information is set in the packet header that is an area where the block code is not applied, the reception apparatus decodes the received packet before performing the block code decoding process. Whether or not possible data is stored can be detected. Therefore, unnecessary execution of decoding processing is avoided, which contributes to reduction in power consumption or filtering processing by software.

  By the way, when the wireless packet shown in FIG. 3 is transmitted, the probability that a bit error occurs is the same in the packet header and the code word. For this reason, in order to correct a bit error that has occurred in the packet header, an error correction code should also be added to the packet header.

  However, if an error occurs in the packet header, the subsequent codeword cannot be decoded in the receiving apparatus. That is, the information stored in the packet header has higher importance or priority than other information. For this reason, it is desirable that the error correction code to be given to the packet header has a higher correction capability than the error correction code given to other information. However, when a plurality of types of error correction codes are used for each wireless packet, each receiving apparatus must be provided with a plurality of error correction decoding circuits. That is, the circuit scale of the decoder of the receiving device is increased. For this reason, the wireless communication system according to the embodiment realizes a function of reproducing correct data without using an error correction code for the packet header. In the following, a function that enables correct data to be reproduced even when an error occurs may be referred to as an error correction function.

FIG. 6 is a diagram for explaining the concept of the error correction function for the packet header. Here, it is assumed that the value of the information stored in the packet header is “Ho”.
The transmitting apparatus makes the header redundant before transmitting the wireless packet. That is, the transmission device generates a plurality of identical packet headers by copying the packet header, and sets them in the head region of the wireless packet. As a result, the packet header is repeatedly transmitted a plurality of times. In the example shown in FIG. 6, “Header Ho” is copied so as to be transmitted eight times.

  The wireless packet with the header made redundant in this way is received by the receiving device. At this time, generally, an error occurs in the bit string constituting the wireless packet with a predetermined probability corresponding to the communication environment or the like. Therefore, this bit error can also occur in the packet header. In the example illustrated in FIG. 6, the fourth header is changed from “Ho” to “H1” and the seventh header is changed from “Ho” to “H2” due to a bit error.

  The receiving device includes a majority unit 40. The majority decision unit 40 examines the values indicated by the received eight headers and detects the header value having the highest occurrence frequency. In the example shown in FIG. 6, “Ho”, “H1”, and “H2” are detected six times, once, and once, respectively. Therefore, in this case, “Ho” is determined to be the most likely (ie most likely) header value. Therefore, the codeword stored and transmitted in the received packet is decoded using this “header Ho”.

  Thus, in the wireless communication system of the embodiment, an error correction function for the packet header is realized without using an error correction code. Here, the correction capability of the error correction function can be enhanced by increasing the number of times the packet header is repeatedly transmitted, for example. Therefore, it is possible to realize an error correction function for correcting an error of a packet header having a higher correction capability than an error correction function for a code word without providing a block decoding circuit for correcting an error of the packet header. it can.

  In the example illustrated in FIG. 6, the majority process is performed on the entire packet header, but the configuration may be such that the majority process is performed on only a part of the packet header. For example, the majority processing may be performed by making only the above-described code word number information redundant. Further, the majority process may be performed by making only the above-described encoding parameter information redundant. Alternatively, the majority processing may be performed by making the code word number information and the encoding parameter information redundant.

FIG. 7 is a block diagram of the majority unit 40 shown in FIG. Note that a plurality of packet headers set in the head region of the received packet are input to the majority decision unit 40.
The decomposition unit 41 decomposes a plurality of packet headers and outputs them one by one. The input register 42 temporarily holds the packet header output from the disassembling unit 41. The pattern storage registers 43-1 to 43-8 hold an input packet header for each header value. The comparison unit 44 compares the packet header held in the input register 42 with the packet header held in the pattern storage registers 43-1 to 43-8, and according to the comparison result, the counter 45- Count up 1-45-8. The counters 45-1 to 45-8 count the number of input packet headers for each header value. Then, the determination unit 46 determines the most likely packet header based on the count values of the counters 45-1 to 45-8.

  FIG. 8 is a flowchart showing the operation of the majority unit 40. Note that the processing according to this flowchart is executed when the receiving device receives a wireless packet. Further, at the start of the processing according to this flowchart, it is assumed that the pattern storage registers 43-1 to 43-8 are empty and the counters 45-1 to 45-8 are reset.

  In step S1, a variable i is initialized. Here, the variable i identifies a plurality of headers set in the radio packet. In step S 2, the header (i-th header) specified by the variable i is extracted and written to the input register 42.

  In step S3, the header held in the input register 42 is compared with the header held in the pattern storage registers 43-1 to 43-8. If the same header as the header held in the input register 42 is held in the pattern storage registers 43-1 to 43-8, in step S4, the monitor register holding the header is changed. The corresponding counter (45-1 to 45-8) is incremented. For example, when the same header as that held in the input register 42 is held in the pattern storage register 43-1, the counter 45-1 is incremented.

  On the other hand, if the same header as that held in the input register 42 is not held in any of the pattern storage registers 43-1 to 43-8, it is held in the input register 42 in step S5. The header is written into any one of the pattern storage registers 43-1 to 43-8. Subsequently, in step S6, the counter (45-1 to 45-8) corresponding to the pattern storage register in which the header is newly written is incremented. For example, when a new header is written in the pattern storage register 43-2, the counter 45-2 is incremented.

  In steps S7 and S8, it is checked whether or not there remains a header for which the processing in steps S2 to S6 has not been executed. If an unprocessed header remains, the variable i is incremented and the process returns to step S2. Thereby, the process of step S2-S6 is performed with respect to the following header. And if the process of step S2-S6 is performed about all the headers, the process after step S11 will be started.

  In step S11, the maximum count value is acquired from the counters 45-1 to 45-8. Subsequently, in step S12, the count value acquired in step S11 is compared with a predetermined threshold value. If the count value is greater than the threshold value, the corresponding header is output in step S13. For example, when the count value of the counter 45-1 is the maximum and the count value is larger than the threshold value, the header held in the pattern storage register 43-1 is used as the header transmitted from the transmission device. Output. When the count value acquired in step S11 is less than or equal to the threshold value, it is determined that the reliability of majority processing is low, and predetermined error processing is executed in step S14.

As described above, in the wireless communication system according to the embodiment, the threshold is introduced in the majority process, so that the reliability of the packet header is improved.
By the way, the data transmitted by the wireless packet may include not only actual data but also communication control information for controlling / managing the actual data. For example, in the example shown in FIG. 9A, not only payload data but also a MAC (Media Access Control) header including information for controlling / managing the payload data is encoded and transmitted. In this case, the MAC header and payload data are transmitted after being divided into a plurality of data units. At this time, each data unit is assigned an error correction code. That is, the MAC header and payload data are transmitted by a plurality of codewords 1 to 5.

  In the example shown in FIG. 9A, the MAC header is stored in codeword 1, and only the payload data is stored in other codewords. Here, the MAC header includes address information such as transmission source information and destination information, information for disassembling / assembling payload data, and the like. Therefore, if a data error occurs in codeword 1 and the error cannot be corrected by the error correction code, not only codeword 1 but also codeword 2 to codeword 5 depend on the correct destination. It will not be acquired. Therefore, it can be said that the codeword in which the MAC header is stored has higher importance or priority than other codewords.

  For this reason, it is desirable to use an error correction code having a correction capability higher than that of other codewords as the codeword storing the MAC header. However, when a plurality of types of error correction codes are used for each wireless packet, each receiving apparatus must be provided with a plurality of error correction decoding circuits, which increases the circuit scale of the decoder.

  Therefore, in the wireless communication system of the embodiment, as shown in FIG. 9B, the payload data is divided into predetermined lengths to generate a plurality of data units, and a MAC header is assigned to each data unit. Subsequently, a plurality of codewords 1 to 6 are generated by assigning an error correction code to each data unit to which the MAC header is assigned. And the radio | wireless packet which stores these some codeword 1-codeword 6 is produced, and the radio | wireless packet is transmitted.

  Thus, in the wireless communication system of the embodiment, the MAC header is stored in each codeword. Therefore, for example, even if a data error occurs in codeword 1 and the error cannot be corrected by the error correction code, the payload data stored in codeword 2 to codeword 6 is It is reproduced using the information of the MAC header stored in each codeword. In this case, it is sufficient to request retransmission only for codeword 1. Therefore, considering the possibility that an error that cannot be corrected even by the error correction code occurs, the data transmission efficiency is improved as a whole as compared with the method shown in FIG.

  However, in the method shown in FIG. 9B, since the MAC header is transmitted redundantly, if the information amount of the MAC header is large, the data transmission efficiency is lowered. Therefore, in FIG. 9B, not all the information stored in the MAC header is given to each data unit, but a part of the information stored in the MAC header. You may make it give only. In this case, information given to each data unit is, for example, transmission source information, destination information, information for disassembling / assembling payload data. Here, as information for disassembling / assembling payload data, for example, a sequence number and / or block number that uniquely identifies a plurality of data units obtained by decomposing the original payload data is used. Can do.

  FIG. 10 is a flowchart of the packet creation procedure shown in FIG. Here, it is assumed that payload data to which a MAC header is attached is stored in a wireless packet.

  In step S21, the MAC header is extracted. In step S22, necessary information is extracted from the extracted MAC header. The information to be extracted here is, for example, a transmission source address and a destination address of payload data. This step S22 is a process that can be arbitrarily executed, and is not necessarily a process that must be executed.

  In step S23, data (data unit) is cut by a predetermined length from the beginning of the payload. In step S24, a sequence number to be assigned to the data unit cut in step S23 is generated. In step S25, MAC information is given to the data unit cut out in step S23. Here, the MAC information is, for example, the information extracted in step S22 and the sequence number generated in step S24. In step S26, a code word is created by giving an error correction code to the data unit to which the MAC information is given.

  In step S27, it is checked whether or not payload data remains. If payload data remains, the process returns to step S23 to cut out the next data unit. On the other hand, if no payload data remains, the process proceeds to step S28, and a plurality of code words obtained by repeatedly executing steps S23 to S26 are connected. In step S29, a header of the wireless packet shown in FIG. 3 is created.

  As described above, in the wireless communication system according to the embodiment, a plurality of codewords are stored in the wireless packet, and information with high importance is included in each codeword. Even if an arbitrary code word in the code word cannot be reproduced, information having high importance can be used when reproducing another code word. Therefore, when an error that cannot be corrected by the error correction code occurs, the amount of data to be retransmitted is reduced, so that improvement in data transmission efficiency is expected as a whole.

  In the wireless communication system shown in FIG. 1, the amount of data transmitted from the master station 1 to each of the slave stations 2-1 to 2-N is small, and each slave station 2-1 to 2-N is connected to the master station 1. The following design can be introduced when there is a large amount of information transmitted to the network. Here, as a usage form in which such a communication state is obtained, for example, each of the slave stations 2-1 to 2-N includes a monitor camera, and each slave station 2- is provided in response to a request from the master station 1. An application or the like that transmits image data from 1 to 2-N to the master station 1 is assumed.

  When the amount of data transmitted from the master station 1 to each slave station 2-1 to 2-N is small and the amount of data transmitted from each slave station 2-1 to 2-N to the master station 1 is large As shown in FIG. 11, each of the slave stations 2-1 to 2-N is longer than the length of the code word stored in the packet transmitted from the master station 1 to each of the slave stations 2-1 to 2-N. The length of the code word stored in the packet transmitted to the master station 1 is increased. Here, if the code word is short, as is well known, the circuit scale of a decoder (error correction decoder) for decoding the code word can be reduced. That is, it is possible to reduce the size of the decoder provided in each of the slave stations 2-1 to 2-N. In a communication system provided with a plurality of slave stations, it is important to reduce the cost, reduce the power consumption, and reduce the size of the slave stations. Therefore, the above-described design contributes to cost reduction and power consumption reduction of the entire wireless communication system.

  In the above-described embodiment, the system constituted by the master station and the slave station has been described. However, the present invention is not limited to this, for example, a system constituted by a base station device and a terminal device, The present invention can also be applied to a system composed of a plurality of terminal devices that have an equal relationship with each other.

It is a block diagram of the radio | wireless communications system concerning embodiment of this invention. It is a block diagram of the radio | wireless communication apparatus concerning embodiment of this invention. It is a figure which shows the structure of the radio | wireless packet used in the radio | wireless communications system of embodiment. (A) is a figure explaining the encoding parameter set for every communication path. (B) And (c) is the figure which showed typically a mode that a wireless packet was transmitted. It is a block diagram of the decoder provided with the function to determine whether a decoding process is performed based on encoding parameter information. It is a figure explaining the concept of the error correction function with respect to a packet header. It is a block diagram of the majority machine shown in FIG. It is a flowchart which shows operation | movement of a majority machine. (A) is a figure which shows the general packet preparation procedure, (b) is a figure which shows the packet preparation procedure in embodiment. It is a flowchart of the packet creation procedure of the embodiment. It is a figure which shows typically the system from which a codeword length differs according to a transmission direction. It is an example of the data transmission sequence of a radio | wireless communications system. It is a figure which shows the structure of the packet containing several codewords.

Explanation of symbols

1 Master station 2-1 to 2-N Slave station 11 Encoder 23 Decoder 31 Header extraction unit 32 Encoding parameter extraction unit 33 Comparison unit 34 Decoding unit 40 Majority units 43-1 to 43-8 Pattern storage register 44 Comparison unit 45- 1-45-8 Counter 46 judgment part

Claims (1)

Break the data into multiple data units,
Giving the communication control information of the data to each of the plurality of data units;
Generating a plurality of codewords by assigning an error correction code to each of the plurality of data units to which the communication control information is attached;
Generate and transmit a packet that stores the plurality of codewords,
Play back multiple data units using the corresponding communication control information,
Check for errors in multiple data units reproduced using corresponding error correction codes,
A wireless communication method for performing a retransmission request for a data unit in which an error is detected.

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